Lumber Calculator
Work out board feet, cubic volume and linear length for sawn lumber in inches, feet, centimetres or metres.
At a glance
- What you enter
- Length of one piece, Nominal width, Nominal thickness, How many pieces, Unit system, Waste and cut allowance
- What you get
- Board feet, nominal, Board feet, dressed, Difference lost to surfacing, Board feet to buy with waste, Volume, Total linear length, Linear length with waste
- Formula shown
- Yes, every step, right below your results.
- Cost and privacy
- Free, no account needed, and nothing you type is stored.
See worked examples ↓ Read the FAQ ↓ Share this calculator ↓
Results are estimates for general information only, always verify with a professional or official source before acting on them.
How to use the Lumber Calculator
- 1 Enter Length of one piece, Measured in the unit you choose below.
- 2 Enter Nominal width, The name on the price tag, so 4 for a 2x4 and 6 for a 1x6.
- 3 Enter Nominal thickness, The name on the price tag, so 2 for a 2x4 and 1 for a 1x6.
- 4 Enter How many pieces
- 5 Enter Unit system, Choose the unit you measured the length in. Width and thickness are always the nominal inch figures from the price tag.
- 6 Enter Waste and cut allowance (%), Added to the linear length and to the priced board feet so short ends and miscuts are covered.
- 7 Press Calculate. You get Board feet, nominal, Board feet, dressed, Difference lost to surfacing, Board feet to buy with waste, Volume, Total linear length, Linear length with waste, and every intermediate step stays visible under "How is this calculated?"
- 8 Change one number at a time to see what moves the result, that is usually the most useful thing a calculator can tell you.
Worked examples
Real numbers run through this calculator. Open any example to load it into the form above and change it.
One 2x4 eight feet long
The board everybody starts with, measured in feet.
You enter
- Length of one piece
- 8
- Nominal width
- 4
- Nominal thickness
- 2
- How many pieces
- 1
- Unit system
- 2
- Waste and cut allowance
- 10%
You get
- Board feet, nominal
- 5.33 bf
- Board feet, dressed
- 3.50 bf
- Difference lost to surfacing
- 1.83 bf
- Board feet to buy with waste
- 5.87 bf
- Volume
- 0.44 cu ft
- Total linear length
- 8.00 ft
- Linear length with waste
- 8.80 ft
The trade figure is 5.33 board feet nominal. The dressed board is 3.5 board feet of actual wood.
Ten 2x4 studs
A small framing or shop project, ten pieces of 2x4 at 8 feet.
You enter
- Length of one piece
- 8
- Nominal width
- 4
- Nominal thickness
- 2
- How many pieces
- 10
- Unit system
- 2
- Waste and cut allowance
- 10%
You get
- Board feet, nominal
- 53.33 bf
- Board feet, dressed
- 35.00 bf
- Difference lost to surfacing
- 18.33 bf
- Board feet to buy with waste
- 58.67 bf
- Volume
- 4.44 cu ft
- Total linear length
- 80.00 ft
- Linear length with waste
- 88.00 ft
50 linear feet of stock, 53.33 nominal board feet.
Five 2x10 joists in metres
A metric measurement of a joist that is nominally 2 by 10 inches.
You enter
- Length of one piece
- 3.60
- Nominal width
- 10
- Nominal thickness
- 2
- How many pieces
- 5
- Unit system
- 4
- Waste and cut allowance
- 10%
You get
- Board feet, nominal
- 98.43 bf
- Board feet, dressed
- 68.28 bf
- Difference lost to surfacing
- 30.14 bf
- Board feet to buy with waste
- 108.27 bf
- Volume
- 8.20 cu ft
- Total linear length
- 59.06 ft
- Linear length with waste
- 64.96 ft
3.6 metres is 141.73 inches, so each joist is 19.68 nominal board feet.
Guides that go with it
Wood Calculator Guide: Calculate Lumber, Board Feet, Cabinet Materials & Project Costs
A wood calculator turns a vague "how much do I need?" into a number you can hand to a lumber yard. By the end of this guide you will be able to measure a project, convert odd dimensions into board fee...
Hardwood vs Softwood: What's the Difference and Which Wood Should You Choose?
You're standing in the lumber aisle or scrolling a supplier's site trying to decide between two boards that look similar but carry very different price tags. One is labelled hardwood, the other softwo...
Types of Lumber Explained: 15 Common Lumber Types and Their Best Uses
Types of Lumber Explained: 15 Common Lumber Types and Their Best Uses If you have ever stood in the lumber aisle and felt your brain go blank, this is for you. By the end of this guide you will be abl...
Frequently asked questions
How do I calculate board feet?
Why is a 2x4 not two inches by four inches?
What is the difference between a board foot and a linear foot?
Is a board foot the same in the United States and the United Kingdom?
How much waste should I allow on a lumber order?
Terms used here
Short, plain-language definitions of the words this calculator uses.